Astronomers using NASA’s James Webb Space Telescope have found evidence that some of the largest galaxies in the early universe may have been much heavier than previously believed, according to ScienceDaily. The results suggest these ancient systems contained many more small stars than earlier estimates allowed for.
The international research team, which included Penn State scientists, studied nine massive galaxies that had already stopped forming new stars billions of years ago. They paired JWST observations with earlier data from the Very Large Telescope to examine the makeup of the galaxies’ light.
By splitting each galaxy’s light into a spectrum, the researchers were able to infer the relative numbers of large bright stars and smaller faint ones. The study found that low-mass stars appear to make up a larger share of the stellar population in these early galaxies than in smaller galaxies such as the Milky Way.
Researchers said one galaxy in particular may have formed less than 1.5 billion years after the Big Bang and could be as much as four times more massive than earlier calculations suggested. The findings, published in Nature Astronomy, could force scientists to rethink models of how galaxies formed and evolved in the young universe.
